


Wish Upon A Star

by I_Am_A_Potato



Category: Undertale (Video Game)
Genre: Dunno how to tag lol, M/M, an amino quota with the prompt "galaxy", i know theres probably spelling errors but im too lazy to fix it, not really referenced but sans and pap are gaster's childs
Language: English
Status: Completed
Published: 2020-12-23
Updated: 2020-12-23
Packaged: 2021-03-10 18:54:23
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,234
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28251972
Author URL: https://archiveofourown.org/users/I_Am_A_Potato/pseuds/I_Am_A_Potato
Summary: Grillby recalls the fond memories he has of the Surface's night sky during a date with Gaster.
Relationships: W. D. Gaster/Grillby
Kudos: 5





	Wish Upon A Star

"A star is an astronomical object consisting of a luminous spheroid of plasma held together by its own gravity. It provides warmth to the planet and provides the light plants need to photosynthesize. At least, that is the science behind it. I have never gazed upon the stars before. I was born in the Underground…"

Gaster lied his skull on Grillby's lap and hummed as a warm hand was placed upon it, rubbing a thumb down the scarred cracks. They were sitting upon the grasses in Waterfall in an area with very little water, staring up at the markings in the ceiling.

Just another little date they'd say. The bar is closed, Sans is watching Papyrus, Gaster got off of work early… it just seemed like a nice night to go out. Getting here was the only issue. Gaster knew Grillby wanted to take him into Waterfall, but had an extreme aversion to the bodies of water there. One slip and he'd die.

Gaster managed to safely maneuver around certain areas, and now they're here, sitting in the soft grass and appreciating each other's company. Gaster loved the comfortable heat from Grillby creeping into his bone marrow, and Grilby found the skeleton's comfortable sighs cute.

"Looking up at the night sky was so wonderful, but lonely without someone to share the experience with…" The fire monster rubbed his thumb over Gaster's cheek softly and himself hummed. "Would you like me to tell you about it, about the sights of the starry night sky?"

"That would be lovely." Gaster smiled in response.

"It was amazing, even as a child and an adult. Deep blue hues behind the bright white pearls of light, hidden amongst the pale passing clouds. Sometimes, we could see a planet from our solar system without the aid of a telescope." He smiled fondly. "Constellations were a fun little thing. Stars that have always lined up coincidentally to form a shape…"

"What was your favorite thing about the night sky?"

Grillby thought of it for a few minutes while his other hand caressed Gaster's head. What was his favorite thing from the night? What was the thing he enjoyed most from the blanket of stars that used to be above him? The serene calm that covered him when he stargazed? Did he enjoy having company more than the sight of the stars?

"I enjoyed many things from the night's lovely gifts. Watching fireflies soar high up to try and obtain the shining light, the company I shared with another person gazing with me, wishing upon the first visible star in the sky…" Grillby looked down at his lover. "Shooting stars, comets, were my favorite."

"A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing…" The scientist mumbled and stared lovingly up at the flame monster. His brilliant orange hues never ceased to amuse to amuse Gaster.

"Every so often, like a rare gift from an other-worldly force, a shooting star would dash across the sky. It was a beautiful little marvel. And… why is it my favorite, you may be thinking." He chuckled a little when more of a smile crept upon the skeleton's face. "You would wish on them. You wish on the shooting stars, hoping and praying that your wish will come true… and I loved that little sense of hope the wishing gave me…"

"Everything sounds like it was quite amazing, Grillby." Gaster held Grillby's free hand and laced their fingers together. He kept his gaze at him, abandoning the thought of staring at the ceiling's false stars. 

"It was…" His tone soured a little. Like many monsters, he too misses the surface.

"Do you want to know something though? Something that would make this dark little world brighter for you?" Gaster scooted further onto Grillby's lap. He hated seeing the other's little drops in his mood. "I am certain you will love it."

"Oh I will, will I?" Grillby chuckled softly again and looked at the hand of his that the skeleton monster on his lap was holding, watching it being moved up to his chest. He could feel the change in magic, the quickened pace Gaster's SOUL pounded against his ribs and felt the false heartbeat it gave off. "What would be so great then? What did you wish to tell me?"

Gaster keeps quiet for a minute, letting Grillby feel his magic. Warm, orange and yellow flames gave contrasting light to the blue tint castes upon Waterfall. He stood out among everything, unlike Gaster in Snowdin. The scientist quite lived that, loved their unique circumstances.

His marrow is warm with Grillby's heat and his own magic surging through them. It was so calm, so calm and soothing. It felt like all his stresses in life were gone and he was flying amongst the clouds. He never wanted these comfortable moments to end.

"I don't mind staying here, down here, unable to see the night sky. It does not bother me, really..." He placed a hand to Grillby's cheek. "... because you're my star, my sun, my beautiful night sky…"

Grillby didn't expect such a thing to be said and gave himself a minute to process it. His flames burned bright and a blueish color covered his face, suggesting that he is a bit embarrassed. Since he is mostly condensed flame, how he blushes is quite different from the average monster. "How… sweet of you to say, Gaster."

"I'm sure you are much more interesting than the shining night, anyhow. Your peculiar flames flicker and stay warm throughout the cold and cast golden waves, your flames change their colors depending on the minerals in your diet, the crackles in your sweet voice…"

"Too kind, your words are." Another happy laugh as he put the hand over Gaster's chest onto the one holding his face. "I never knew you were such a romantic."

"I learned from the best." Gaster smirked a little and the two shared another moment of chuckles.

The silence between the two was comfortable. No one felt pressured to speak and disrupt the peace of the quietness. The mist was cold against Gaster's bones and sizzled against Grillby's flames, said flames keeping the shorter monster warm.

The star spots in the ceiling flickered as light from the Surface fluttered down through them. Gaster knew they could never compare to what Grillby remembered. He seemed like he really missed the fondness of up above…

"From my studies, observing comets is an uncommon experience. You called them shooting stars, yes? And they were quite bright?" He continued when his lover nodded. "If the ceiling here is our sky, and the holes above are the stars, wouldn't you be my comet? Wouldn't you be my brilliant, shining, shooting star?"

"Am I now?" Grillby put his free hand back to Gaster's cheek to stroke his thumb at the deep scar yet again. So smooth, with an occasional bump or two. Little imperfections that make him even more wonderful.

"I always look forward to the moments we have together. Truly, you're the star that brightens my world, the comet that I would wish upon and hope to see every night…" Another smile. There was another smile on his face, one only Grillby is allowed to see. "I love you, Grillby."

"I love you too, Gaster."


End file.
